In this section, we describe the restricting methodology for the malicious user accounts in the Algorand blockchain. Here, we refer malicious user accounts as the ones using cryptocurrency transactions for either criminal activities or social engineering attacks. A user in a blockchain network can have multiple accounts with dedicated transaction history. Since our proposed method is based on transaction history, we evaluate each account against its own transaction history. For the sake of simplicity, we will henceforth refer to each user account as a separate user. We formulate and analyze the strategy for responding to users carrying out illicit activities by honest users assigned as validators. To formulate the reputation based restricting methodology, it is imperative to understand the consensus protocol of the Algorand blockchain. For the readers not familiar with Algorand blockchain consensus protocol, a brief explanation for the same is given in Appendix . We follow the notation convention of Algorand [1]} with our modifications wherever required. The list of notations is summarized in Table REF .
